Teleconferencing systems enable a plurality of telephone users to participate in a telephone conference call using a telecommunications device referred to as a “bridge”. A bridge has a plurality of ports, each for being connected to a telephone line from one of the participants, and enabling that participant to be connected to the call.
Some teleconferencing systems require participants to each have a security number or pass code, so that only those callers authorized to participate are connected to one of the ports. Pass codes are used to prevent unintended callers from dialing in and eavesdropping, and also prevent callers from using the bridge to make unauthorized calls or conduct fraudulent activities. Pass codes are entered by a caller at his/her telephone in response to a prompt from a voice response unit (VRU). The VRU provides one or more voice messages that instruct the caller and lead him or her through the steps of correctly entering digits of the pass code. The VRU then compares the entered pass code to a list of authorized pass codes.
Bridges may be privately operated (e.g., by a large company that has its own telecommunications equipment), or publicly operated by a telephone company as part of the public switched telephone network (PSTN). An example of a teleconferencing system that uses a scheduler for setting up conference calls is disclosed in U.S. Pat. No. 6,411,605, issued to Vance et al., commonly owned with the present application, and hereby incorporated by reference.
The teleconferencing bridge and the associated equipment for operating the bridge can be costly. In order to save some of this cost, some central office switches may have bridges built-in as part of the switch (e.g., the DMS-100 and DMS-250 switches sold by Nortel Networks Corporation, Ontario, Canada.). However to provide security for teleconferencing participants, a VRU and other equipment is needed. Such equipment is placed at the switch (at the lines connecting the bridges to the switching circuitry) so that pass codes may be entered and screened as part of setting up a conference call. However the equipment is costly and can off-set all the savings from having the bridges built into the switch.